Street sweeper power transmission couplings

ABSTRACT

A rotational power transmission connection for use in street sweepers to couple together driving and driven parts one of which is subject to abnormal rotative resistances, the parts having opposed conical surfaces one of which contains a deformed elastomeric ring engaging and capable of slippage on the opposing conical surface. The coupling has particular applicability for use in pairs to mount a replaceable broom core.

United States tent 1 1 1111 3,726,109

Mortensen Apr. 10, 1973 54] STREET SWEEPER POW 2,992,844 7/1961 Williams..287/52,06

TRANSMISSION COUPLENGS 3,649,985 3/1972 Hunt ..15 179' Inventor: DonaldMomnsen, Upland, FOREIGN PATENTS OR APPLICATIONS Calif.

530,081 12/1940 Great Britain ..l5/79 [73] Assignee: Wayne ManufacturingCompany,

Pomona Cahf" Primary ExaminerEdward L. Roberts [22] Filed: Sept. 27,1971 Attorney-H. Calvin White et al.

[21] Appl. No.: 183,984 [57] ABSTRACT [52] U S Cl 64/30 A 15/49 R 15/82A rotational power transmission connection for use in C 64730 D 2837/52street sweepers to couple together driving and driven 51 1m. 01 .Fl6b7702 Parts one which is Subject to abnormal Native [58] Field of Search..l5/ 179l83, siswnces, the Parts having pp conical Surfaces 50 R, 50 C,49 R, 49 C, 82, 83; 287/5201, one of which contains a deformedelastomeric ring en- 52 5107; 4 30 1 30 gaging and capable of slippageon the opposing coni- 29/117 cal surface. The coupling has particularapplicability for use in pairs to mount a replaceable broom core. 56 R fC'ted 1 e erences l 6 Claims, 6 Drawing Figures UNITED STATES PATENTS874,267 12/1907 Wagner ..287/52.07

PATEFHEUAPR 1 @1815 3,726,109

SHEET 1 OF 2 INVENTO/Q DOA/0L0 G Mo/eTEMsEA/ STREET SWEEPER POWERTRANSMISSION COUPLINGS BACKGROUND OF THE INVENTION Components ofconventional street sweepers such as rotary pickup brooms, gutter broomsand debris conveyors have rotational drives usually powered directly orindirectly by the sweeper vehicle engine. Any of these components may besubjected in their operation to resistances setting up abnormal torquesin the drive transmissions which advantageously could be relieved toprevent stoppage or overstress conditions as they arise.

SUMMARY OF THE INVENTION The present invention achieves this generalobjective broadly by interposition in the power transmission of one or apair of novel couplings having inherent capacities for slippage as anabnormal resistance or overstress condition arises.

In more specific reference to the coupling, the invention has for itsobject to provide a power transmitting connection between rotatablydriven sweeper parts, comprising what may be termed inner and outersections characterized by their presentation of opposed conicalsurfaces, one of which carries a deformable elastomeric ring whichnormally transmits without slippage the drive from one section to theother but which upon abnormal resistance to their relative rotation iscapable of slippage on the conical surface which it engages.

This conical surface and elastomeric ring relation presents a number ofadvantages including greater facility with which the coupling andsections may be assembled in accurately guided axial alignment,simplicity in the coupling structure, and effective utilization of asimple elastomeric ring such as a deformed O-ring to achieve both powertransmission and maintenance of a slippage factor.

The invention has particular applicability to the mounting and drivingof replaceable sweeper pickup brooms within which the couplings areinstalled in opposite ends of a tubular broom core so that the lattercarries the outer coupling sections while the broom drive shaft mountsthe inner sections. As will appear, at least one of the sections isaxially adjustable relative to the outer section to controllably varythe clearance between the opposed conical surfaces and therefor thedegree of deformation of the elastomeric ring and its resistance toslippage.

The invention has for a further and specific object to so utilize thecoupling sections within a broom core that when the broom requiresreplacement, the drive components can readily be disassembled with theouter conical sections remaining attached to the core shell, andreassembled utilizing a similar replacement core easily and accuratelymountable on the drive shaft which retains the inner conical sections.

The invention and its applicability to the driving of a sweepercomponents referred to in the foregoing, will be more fully understoodfrom the following detailed description of the accompanying drawings:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a sectional illustration ofthe invention as applied to the mounting of a road sweeper pickup broomon its drive shaft assembly;

FIG. 2 shows in cross section a variational form of the invention asused for power transmission to a street sweeper gutter broom;

FIG. 3 is a sectional view showing diagramatically the generalconfiguration of a street sweeper belt or chain type conveyor;

FIG. 4 is an enlarged cross section taken on line 4-4 of FIG. 3 showinga drive transmission in accordance with the invention;

FIG. 5 is a view similar to FIG. 3 illustrative of a single rotary typesweeper conveyor; and

FIG. 6 is an enlarged fragmentary cross section on line 66 of FIG. 5illustrative of the shaft drive.

Referring first to the pickup broom assembly appearing in FIG. I, thebroom generally indicated at 10 is shown to be carried in a usual mannerby arms 11 and 12 mounted to the sweeper vehicle for swinging or otherdisplacement in accordance with road surface irregularities or otherlike conditions encountered by the broom. The latter is mounted forrotation on its drive shaft 13, the rotation being transmitted by way ofthe later described conical coupling sections to the tubular broom core14 and bristles 15. It will be understood that the bristles may bemounted to the core 14 in any suitable manner as within holders 16applied annularly or spirally about the core and held thereto. Shaft 13is driven by stub shaft 17 received within counterbore 18 and driven bymotor M, the housing of which has an extension 19 received and fixedwithin the arm 12.

At its opposite end the shaft 13 is rotatably carried within arm 11 byway of bearing retainer 20 removably held to the arm by bolts 21, theretainer 20 having curved flange 22 which engages and positions theouter race ring 24 of roller bearing 23. The inner race ring 25 is heldto the shaft 13 for rotation therewith.

One end of the broom core 14 contains what may be termed an outerconical coupling section 26 temporarily or permanently welded orotherwise secured to the core at 27. Within its opposite end the core 14contains a similar outer coupling section 28 which as in the case ofsection 26 may be permanently or impermanently secured at 29 to thecore. The coupling sections 26 and 28 have inner conical surfaces 30 and31 of annular cross section which receive the correspondingly taperedsurfaces of inner sections 32 and 331, the latter being formed as atruncated conical enlargement of the driven end of shaft 13 keyed at 332to the motor shaft within annulus or clamp ring 333. Clearances at 33and 36 between the inner and outer conical surfaces may be maintained byproviding suitable shoulders at 35 and 37 engageable respectively byinner sections 32 and 331 in accordance with the degree of relativeaxial adjustment of the inner sections on the shaft 13.

Such adjustment is effected by screw 39 threaded at 40 into the shaft 13and adjustable to shift the shaft axially and in so doing to bringsections 32 and 331 relatively together or apart while maintaining fixedrelation between section 32 and race ring 25 by reason of theirengagement at 34. Section 32 may or may not be positively driven by theshaft 13 although a driving relation may be assumed by the showing ofkey 42.

interposed between the conical surfaces are elastomeric rings 43 and 44shown to be accommodated within annular recesses 45 and 46 within theouter sections 28 and 26. It will be understood that these rings may becontained within either the outer or inner conical surfaces although theillustrated arrangement is preferred. The drawing shows the elastomericrings in deformed condition by reason of their pressural confinementagainst the inner conical surfaces. As installed and while unstressedthe rings may be essentially circular in cross section similar tocommonly termed rings. By adjustment of screw 39 the clearances at 31and 33 and therefore the degree of compressive deformation of rings 43and 44 may be subject to variation depending upon the desired brushresistance to rotation with the drive shaft 13. Normally the adjustmentwill be such that as the brush encounters abnormal resistance topositively driven rotation, the elastomeric rings are capable ofrotation on and about the inner conical sections until such resistanceis relieved.

FIG. 2 illustrates a single coupling adaptation of the invention to thedrive of a conventional gutter broom 50 mounted to the sweeper vehiclein any suitable manner and driven by motor 51 carried by suitablesupport 52. The driven motor shaft 53 is keyed at 54 within annulus orclamp ring 55 to the inner coupling section 56 having a frusto-conicalsurface 57 received within correspondingly tapered surface 58 of theouter coupling section 59 which may be integrated in any suitable mannerwith the gutter broom structure 60. As before, one or the other ofsections 56 and 59 may be recessed to contain an elastomeric ring 61variably deformable by adjustment of screw 63 threaded into the shaft 53and bearing against the washer 64.

By adjustment of the screw, the inner section 56 may be shifted axiallyof the shaft to vary the clearance between the section and therefore theextent of deformation of the elastomeric ring 61. As the gutter broomencounters abnormal resistance to rotation by the motor 51, theelastomeric ring 61 becomes capable of slippage on the inner conesurface until the resistance normalizes.

In the variational form of the invention appearing in FIGS. 3 and 4 thedual cone section drive is shown to be used to power a conventional roadsweeper endless belt or chain conveyor 66 operating within housing 67 todisplace into dirt chamber 68 debris received from the pickup broom 69.Here the conveyor is shown to comprise squeeges 70 carried by arms 71fixed to tubular member 72 which in turn is fixedly received at itsopposite ends within outer coupling sections 74 and 75 having innerfrusto-conical surfaces 76 and 77 within which are retained the deformedO-rings 78 and 79. One of the conveyor shafts 80 is driven by motor 81having its stub shaft 82 received within and keyed to the inner conicalcoupling section 83. At its opposite end the shaft mounts the secondinner coupling section 183 and is journalled for rotation within bearing84 carried by the conveyor housing.

' As before, the shaft and the clearances at 85 and 86 between theconical coupling surfaces are variable by adjustment of screw 87threaded into the shaft to adjust accordingly the deformation of rings78 and 79 and therefore the slippage potential of ring 79 on the innersection 8. In this instance the conveyor is shown to be positive ydriven only at the motor end of the shaft by slippage-capable powertransmission through ring 79, the opposite end of the shaft beingrotatable within the inner section 183. y

In reference to the further variational form of the invention appearingin FIGS. 5 and 6, here the conveyor is shown to comprise a single shaft90 carrying squeegee arms 91 rotatable within the housing 92 to displacedebris into the chamber 93. As shown in FIG. 6 the arms 91 are carriedby outer coupling section 94 mounted to tubular member 95 correspondingto member 72 in FIG. 4. The conveyor shaft 96 is driven by the motorshaft 97 received within the inner coupling section 98. As before, thepower transmission with slippage capacity is by way of the elastomericring 99 received within recess 100 in the outer section.

As will be understood without necessity for repetitions description, theopposite end of shaft 96 may be accommodated for axial adjustment andreceived within inner and outer housing-supported coupling sections aspreviously described in reference to FIG. 4.

We claim:

1. In a street sweeper, a power transmitting coupling betweenrotationally driving and driven parts comprising inner and outersections having opposed conical surfaces, and an elastomeric ringcontained in an annular recess in one of said surfaces and engaging theother surface and functioning to transmit rotational drive from one tothe other of said sections.

2. A drive according to claim 1, including means for deforming said ringunder variable radial compression permitted by clearance between saidconical surfaces.

3. A drive according to claim 2, in which said ring is capable ofslippage on the conical surface which it engages in response to relativerotational resistance between the sections.

4. A drive according to claim 2, in which said sections are axiallyrelatively movable and adjustable, and stop means is provided to limitsuch movement and deformation of the ring.

5. A drive according to claim 2, including also a shaft extending withinsaid inner section, and means carried by the shaft for adjustablyvarying said clearance and compression of the ring.

6. A drive according to claim 5, in which said means includes a boltheld against axial movement and threaded into said shaft.

sena e

1. In a street sweeper, a power transmitting coupling betweenrotationally driving and driven parts comprising inner and outersections having opposed conical surfaces, and an elastomeric ringcontained in an anNular recess in one of said surfaces and engaging theother surface and functioning to transmit rotational drive from one tothe other of said sections.
 2. A drive according to claim 1, includingmeans for deforming said ring under variable radial compressionpermitted by clearance between said conical surfaces.
 3. A driveaccording to claim 2, in which said ring is capable of slippage on theconical surface which it engages in response to relative rotationalresistance between the sections.
 4. A drive according to claim 2, inwhich said sections are axially relatively movable and adjustable, andstop means is provided to limit such movement and deformation of thering.
 5. A drive according to claim 2, including also a shaft extendingwithin said inner section, and means carried by the shaft for adjustablyvarying said clearance and compression of the ring.
 6. A drive accordingto claim 5, in which said means includes a bolt held against axialmovement and threaded into said shaft.